Prismatic Zircon in Kashmir Sapphire

Prismatic elongated zircon in Kashmir sapphire. Photomicrograph by Narint Jaisanit; field of view 2.88 mm.
Recently, the author examined a faceted blue oval sapphire. Standard gemological properties and chemical analysis indicated a geographic origin of Kashmir. Microscopic examination revealed internal graining, fine particle banding, and fingerprint inclusions. Interestingly, elongated zircon inclusions were also observed, displaying attractive birefringent interference colors under cross-polarized filters caused by the splitting of light in the doubly refractive crystals (see above). Kashmir sapphire is one of the rarest and most valuable gemstones in the world, renowned for its beauty and quality, and this stone was no exception.